For screenshots I use this little snippet:

  ;; Paste image to orgmode https://stackoverflow.com/questions/17435995/paste-an-image-on-clipboard-to-emacs-org-mode-file-without-saving-it
  (defun my-org-screenshot ()
    "Take a screenshot into a time stamped unique-named file in the
  same directory as the org-buffer and insert a link to this file."
    (interactive)
    (org-display-inline-images)
    (setq filename
          (concat
           (make-temp-name
            (concat (file-name-nondirectory (buffer-file-name))
                    "_imgs/"
                    (format-time-string "%Y%m%d_%H%M%S_")) ) ".png"))
    (unless (file-exists-p (file-name-directory filename))
      (make-directory (file-name-directory filename)))
    ; take screenshot
    (if (eq system-type 'darwin)
        (call-process "screencapture" nil nil nil "-i" filename))
    (if (eq system-type 'gnu/linux)
        (call-process "import" nil nil nil filename))
    ; insert into file if correctly taken
    (if (file-exists-p filename)
      (insert (concat "[[file:" filename "]]"))))